I would compare the entire package. Stan Pac preplots upgrades so maybe they include some extras with the suite??????
When we looked at Hawthorn in Pavilion Park, Pulte preplotted nothing and charged for everything including a gas stub to the backyard.
Not sure what the incentives are now, but Stafford was offering $7500 in the design center in addition to their preplots (included fireplaces in some plans, recessed lights, jboxes, slider doors). You can ask at the sales center and they probably will tell u what is preplotted.
U also need to consider the neighborhoods. One goes to Tustin schools and the other to Irvine. Neither have low taxes, but I think Stafford is probably lower than Juniper.
And then there is lot size, proximity to street noise.
Add everything up for the lots u r looking at and see if you can negotiate some upgrades.